This project includes the development of biochemical and target-focused assays based on specific protein or nucleic acid targets implicated in disease. The assay designs are considered in the context of analysis and progression strategies for evaluation of a wide range of compound classes using high throughput screening technologies. There is a strong emphasis on methods development research to advance assay and lead discovery efficiency. Complementing these activities we also explore and devise approaches for the interrogation of complex chemical libraries (e.g., natural product extracts, mRNA display). The work from this program is used to support a range of grant applications and prototype projects. The following are on-going: Targeting protein palmitoylation with small molecules. In collaboration with A. Banerjee (NICHD, NIH) we have developed 1536-well compatible protein palmitoyl acyl transferase assays to evaluate chemical libraries for potential inhibitors of the enzyme as possible therapeutic leads for the large number of diseases to which this class of enzyme have been linked. These compounds are also anticipated to have value as structural, functional and pharmacological probes. Strategies for the discovery of small molecule ligands of RNA. In collaboration with Prof. N. Baird (U. Sciences) we are exploring assay designs to probe the interaction of small molecules with non-coding gene-regulatory mRNAs. The research has the potential of the discovery of novel antibiotics or anticancer agents. Assay development to enable discovery of novel small molecule antagonists of the receptor guanylate cyclase Npr1. In collaboration with M. Hoon (NIDCR, NIH) we have developed assays of the b-type natriuretic peptide (BNP) receptor, Npr1. Recently the agonist, BNP was shown to be required for the transmission of itch sensation between peripheral and spinal cord nerves. The Npr1 assays were employed in large-scale chemical library screening to identify novel natriuretic peptide receptor antagonists to investigate the potential of pharmacological treatments of chronic itch, a condition that results in long-term unremitting urge to scratch that significantly degrades the quality of life for sufferers (Solinski HJ et al., in press). SIRPa-CD47 Protein-protein interaction. In collaboration with T. Miller (Paradigm Shift Therapeutics) and D. Roberts (NCI, NIH) our goal is to leverage the broad potential of CD47 as a molecular target in a number of tumors to create therapeutics that protect normal tissue from chemo and radiation therapy while differentially enhancing the effects of these therapies on the tumor. We designed and validated several biochemical SIRPa-CD47 protein-protein interaction assays (Miller T et al., submitted). Using these assays we are investigating the potential SIRPa-CD47 complex disruption activity of several compounds identified from large-scale high throughput chemical library screening. Chorismate mutase inhibitors. In collaboration with J. Padia (PrimeTime Life Sciences) this project seeks to develop a quantitative high throughput screening (qHTS) assay for the identification of small molecule inhibitors of chorismate mutase (CM). CM is an important enzyme found in plants and microorganisms required for the biosynthesis of the aromatic amino acids phenylalanine and tyrosine. Mammals cannot carry out the de novo biosynthesis of aromatic amino acids and must rely on dietary sources. Thus, a potent and selective drug-like inhibitor of CM would be a valuable antimicrobial agent, particularly for antimicrobial resistant infections. Targeting G proteins with small molecules. Fibrous dysplasia of bone (McCune-Albright syndrome) is a hyperfunctioning endocrinopathy resulting from mis-sense mutations in the small -subunit of the G-protein, Gs leading to increased levels of cellular cAMP. The aim of this project is to develop biochemical and cell-based assays suitable for evaluating the activity and coupling of G proteins to their GPCRs and effector adenylyl cyclase (Getz RA et al., 2019). For example by enabling a quantitative high throughput screening assay using the R201C mutant form of Gs to identify small molecules capable of antagonizing the R201C Gs adenylyl cyclase-activating conformation.